Mandan, Hidatsa, and Arikara Nation

Mandan, Hidatsa, and Arikara Nation, also known as the Three Affiliated Tribes, are a Native American group comprising a union of the Mandan, Hidatsa, and Arikara peoples, whose native lands ranged across the Missouri River basin in the Dakotas. As a result of hardship, losses from infectious disease and forced relocations, these three peoples came together in the late 19th century.

As of 1870 the nation is based at the Fort Berthold Reservation in northwestern North Dakota. The Tribe reported a total enrollment of 15,309 registered tribe members in March 2016. Nearly 6,000 live on the reservation; others live and work elsewhere.

In 2010 the tribe passed amendments specifying "blood quantum," or minimum amounts of tribal ancestry to qualify individuals for membership and as candidates for public office. Individuals must have at least 1/8 Mandan, Hidatsa, or Arikara ancestry (the equivalent of one full-blooded great-grandparent) to become an enrolled member of the MHA Nation. Before the amendment's passage on November 3, 2010, membership was open to any individual with documented "Lineal Descent," with at least one parent being a member of the MHA Nation.

In the same election, the membership of the Three Affiliated Tribes voted on an amendment regarding the eligibility of individuals as candidates for public office of the tribe. As of November 3, 2010, a person must have at least 1/4 Mandan, Hidatsa, or Arikara ancestry (the equivalent of one full-blooded grandparent) to qualify as a candidate for the Tribal Business Council. The prior requirement to run for public office was open to any person who was a member of the Three Affiliated Tribes regardless of blood degree.

On July 30, 2013, the people of the Three Affiliated Tribes held a Secretarial Election on two proposed amendments to the Constitution. The first changed the composition of the Tribal Business Council from 1 to 2 representatives per "segment" (of the Fort Berthold Indian Reservation), and added an additional representative for each segment with a population of at least 700. The Amendment passed by a vote of 303 to 205, out of 1,249 registered voters. The second amendment created a process for petition and voting for each segment to remove any councilman, and allowed for a segment to hold a special election in case of a vacancy on the Council. This Amendment passed by a vote of 443 to 65.

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